2006-08-29 Havoc Pennington <hp@redhat.com>

	* dbus/dbus-sysdeps-util.c, dbus/dbus-sysdeps-util-unix.c: change
	from Ralf Habacker to move UNIX-specific sysdeps into a separate file.

1 files changed, 740 insertions, 0 deletions

diff --git a/dbus/dbus-sysdeps-util-unix.c b/dbus/dbus-sysdeps-util-unix.c
new file mode 100644
index 00000000..404be44b
--- /dev/null
+++ b/dbus/dbus-sysdeps-util-unix.c
@@ -0,0 +1,740 @@
+/* -*- mode: C; c-file-style: "gnu" -*- */
+/* dbus-sysdeps-util-unix.c Would be in dbus-sysdeps-unix.c, but not used in libdbus
+ * 
+ * Copyright (C) 2002, 2003, 2004, 2005  Red Hat, Inc.
+ * Copyright (C) 2003 CodeFactory AB
+ *
+ * Licensed under the Academic Free License version 2.1
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+#include "dbus-sysdeps.h"
+#include "dbus-internals.h"
+#include "dbus-protocol.h"
+#include "dbus-string.h"
+#define DBUS_USERDB_INCLUDES_PRIVATE 1
+#include "dbus-userdb.h"
+#include "dbus-test.h"
+
+#include <sys/types.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <grp.h>
+#include <sys/socket.h>
+#include <dirent.h>
+#include <sys/un.h>
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+
+/**
+ * @addtogroup DBusInternalsUtils
+ * @{
+ */
+
+/**
+ * Does the chdir, fork, setsid, etc. to become a daemon process.
+ *
+ * @param pidfile #NULL, or pidfile to create
+ * @param print_pid_fd file descriptor to print daemon's pid to, or -1 for none
+ * @param error return location for errors
+ * @returns #FALSE on failure
+ */
+dbus_bool_t
+_dbus_become_daemon (const DBusString *pidfile,
+		     int               print_pid_fd,
+                     DBusError        *error)
+{
+  const char *s;
+  pid_t child_pid;
+  int dev_null_fd;
+
+  _dbus_verbose ("Becoming a daemon...\n");
+
+  _dbus_verbose ("chdir to /\n");
+  if (chdir ("/") < 0)
+    {
+      dbus_set_error (error, DBUS_ERROR_FAILED,
+                      "Could not chdir() to root directory");
+      return FALSE;
+    }
+
+  _dbus_verbose ("forking...\n");
+  switch ((child_pid = fork ()))
+    {
+    case -1:
+      _dbus_verbose ("fork failed\n");
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to fork daemon: %s", _dbus_strerror (errno));
+      return FALSE;
+      break;
+
+    case 0:
+      _dbus_verbose ("in child, closing std file descriptors\n");
+
+      /* silently ignore failures here, if someone
+       * doesn't have /dev/null we may as well try
+       * to continue anyhow
+       */
+      
+      dev_null_fd = open ("/dev/null", O_RDWR);
+      if (dev_null_fd >= 0)
+        {
+          dup2 (dev_null_fd, 0);
+          dup2 (dev_null_fd, 1);
+          
+          s = _dbus_getenv ("DBUS_DEBUG_OUTPUT");
+          if (s == NULL || *s == '\0')
+            dup2 (dev_null_fd, 2);
+          else
+            _dbus_verbose ("keeping stderr open due to DBUS_DEBUG_OUTPUT\n");
+        }
+
+      /* Get a predictable umask */
+      _dbus_verbose ("setting umask\n");
+      umask (022);
+      break;
+
+    default:
+      if (pidfile)
+        {
+          _dbus_verbose ("parent writing pid file\n");
+          if (!_dbus_write_pid_file (pidfile,
+                                     child_pid,
+                                     error))
+            {
+              _dbus_verbose ("pid file write failed, killing child\n");
+              kill (child_pid, SIGTERM);
+              return FALSE;
+            }
+        }
+
+      /* Write PID if requested */
+      if (print_pid_fd >= 0)
+	{
+	  DBusString pid;
+	  int bytes;
+	  
+	  if (!_dbus_string_init (&pid))
+	    {
+	      _DBUS_SET_OOM (error);
+              kill (child_pid, SIGTERM);
+	      return FALSE;
+	    }
+	  
+	  if (!_dbus_string_append_int (&pid, child_pid) ||
+	      !_dbus_string_append (&pid, "\n"))
+	    {
+	      _dbus_string_free (&pid);
+	      _DBUS_SET_OOM (error);
+              kill (child_pid, SIGTERM);
+	      return FALSE;
+	    }
+	  
+	  bytes = _dbus_string_get_length (&pid);
+	  if (_dbus_write (print_pid_fd, &pid, 0, bytes) != bytes)
+	    {
+	      dbus_set_error (error, DBUS_ERROR_FAILED,
+			      "Printing message bus PID: %s\n",
+			      _dbus_strerror (errno));
+	      _dbus_string_free (&pid);
+              kill (child_pid, SIGTERM);
+	      return FALSE;
+	    }
+	  
+	  _dbus_string_free (&pid);
+	}
+      _dbus_verbose ("parent exiting\n");
+      _exit (0);
+      break;
+    }
+
+  _dbus_verbose ("calling setsid()\n");
+  if (setsid () == -1)
+    _dbus_assert_not_reached ("setsid() failed");
+  
+  return TRUE;
+}
+
+
+/**
+ * Creates a file containing the process ID.
+ *
+ * @param filename the filename to write to
+ * @param pid our process ID
+ * @param error return location for errors
+ * @returns #FALSE on failure
+ */
+dbus_bool_t
+_dbus_write_pid_file (const DBusString *filename,
+                      unsigned long     pid,
+		      DBusError        *error)
+{
+  const char *cfilename;
+  int fd;
+  FILE *f;
+
+  cfilename = _dbus_string_get_const_data (filename);
+  
+  fd = open (cfilename, O_WRONLY|O_CREAT|O_EXCL|O_BINARY, 0644);
+  
+  if (fd < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to open \"%s\": %s", cfilename,
+                      _dbus_strerror (errno));
+      return FALSE;
+    }
+
+  if ((f = fdopen (fd, "w")) == NULL)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to fdopen fd %d: %s", fd, _dbus_strerror (errno));
+      close (fd);
+      return FALSE;
+    }
+  
+  if (fprintf (f, "%lu\n", pid) < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to write to \"%s\": %s", cfilename,
+                      _dbus_strerror (errno));
+      
+      fclose (f);
+      return FALSE;
+    }
+
+  if (fclose (f) == EOF)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to close \"%s\": %s", cfilename,
+                      _dbus_strerror (errno));
+      return FALSE;
+    }
+  
+  return TRUE;
+}
+
+
+/**
+ * Changes the user and group the bus is running as.
+ *
+ * @param uid the new user ID
+ * @param gid the new group ID
+ * @param error return location for errors
+ * @returns #FALSE on failure
+ */
+dbus_bool_t
+_dbus_change_identity  (dbus_uid_t     uid,
+                        dbus_gid_t     gid,
+                        DBusError     *error)
+{
+  /* setgroups() only works if we are a privileged process,
+   * so we don't return error on failure; the only possible
+   * failure is that we don't have perms to do it.
+   * FIXME not sure this is right, maybe if setuid()
+   * is going to work then setgroups() should also work.
+   */
+  if (setgroups (0, NULL) < 0)
+    _dbus_warn ("Failed to drop supplementary groups: %s\n",
+                _dbus_strerror (errno));
+  
+  /* Set GID first, or the setuid may remove our permission
+   * to change the GID
+   */
+  if (setgid (gid) < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to set GID to %lu: %s", gid,
+                      _dbus_strerror (errno));
+      return FALSE;
+    }
+  
+  if (setuid (uid) < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to set UID to %lu: %s", uid,
+                      _dbus_strerror (errno));
+      return FALSE;
+    }
+  
+  return TRUE;
+}
+
+/** Installs a UNIX signal handler
+ *
+ * @param sig the signal to handle
+ * @param handler the handler
+ */
+void
+_dbus_set_signal_handler (int               sig,
+                          DBusSignalHandler handler)
+{
+  struct sigaction act;
+  sigset_t empty_mask;
+  
+  sigemptyset (&empty_mask);
+  act.sa_handler = handler;
+  act.sa_mask    = empty_mask;
+  act.sa_flags   = 0;
+  sigaction (sig,  &act, NULL);
+}
+
+
+/**
+ * Removes a directory; Directory must be empty
+ * 
+ * @param filename directory filename
+ * @param error initialized error object
+ * @returns #TRUE on success
+ */
+dbus_bool_t
+_dbus_delete_directory (const DBusString *filename,
+			DBusError        *error)
+{
+  const char *filename_c;
+  
+  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+
+  filename_c = _dbus_string_get_const_data (filename);
+
+  if (rmdir (filename_c) != 0)
+    {
+      dbus_set_error (error, DBUS_ERROR_FAILED,
+		      "Failed to remove directory %s: %s\n",
+		      filename_c, _dbus_strerror (errno));
+      return FALSE;
+    }
+  
+  return TRUE;
+}
+
+/** Checks if a file exists
+*
+* @param file full path to the file
+* @returns #TRUE if file exists
+*/
+dbus_bool_t 
+_dbus_file_exists (const char *file)
+{
+  return (access (file, F_OK) == 0);
+}
+
+/** Checks if user is at the console
+*
+* @param username user to check
+* @param error return location for errors
+* @returns #TRUE is the user is at the consolei and there are no errors
+*/
+dbus_bool_t 
+_dbus_user_at_console (const char *username,
+                       DBusError  *error)
+{
+
+  DBusString f;
+  dbus_bool_t result;
+
+  result = FALSE;
+  if (!_dbus_string_init (&f))
+    {
+      _DBUS_SET_OOM (error);
+      return FALSE;
+    }
+
+  if (!_dbus_string_append (&f, DBUS_CONSOLE_AUTH_DIR))
+    {
+      _DBUS_SET_OOM (error);
+      goto out;
+    }
+
+
+  if (!_dbus_string_append (&f, username))
+    {
+      _DBUS_SET_OOM (error);
+      goto out;
+    }
+
+  result = _dbus_file_exists (_dbus_string_get_const_data (&f));
+
+ out:
+  _dbus_string_free (&f);
+
+  return result;
+}
+
+
+/**
+ * Checks whether the filename is an absolute path
+ *
+ * @param filename the filename
+ * @returns #TRUE if an absolute path
+ */
+dbus_bool_t
+_dbus_path_is_absolute (const DBusString *filename)
+{
+  if (_dbus_string_get_length (filename) > 0)
+    return _dbus_string_get_byte (filename, 0) == '/';
+  else
+    return FALSE;
+}
+
+/**
+ * stat() wrapper.
+ *
+ * @param filename the filename to stat
+ * @param statbuf the stat info to fill in
+ * @param error return location for error
+ * @returns #FALSE if error was set
+ */
+dbus_bool_t
+_dbus_stat (const DBusString *filename,
+            DBusStat         *statbuf,
+            DBusError        *error)
+{
+  const char *filename_c;
+  struct stat sb;
+
+  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+  
+  filename_c = _dbus_string_get_const_data (filename);
+
+  if (stat (filename_c, &sb) < 0)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "%s", _dbus_strerror (errno));
+      return FALSE;
+    }
+
+  statbuf->mode = sb.st_mode;
+  statbuf->nlink = sb.st_nlink;
+  statbuf->uid = sb.st_uid;
+  statbuf->gid = sb.st_gid;
+  statbuf->size = sb.st_size;
+  statbuf->atime = sb.st_atime;
+  statbuf->mtime = sb.st_mtime;
+  statbuf->ctime = sb.st_ctime;
+
+  return TRUE;
+}
+
+
+/**
+ * Internals of directory iterator
+ */
+struct DBusDirIter
+{
+  DIR *d; /**< The DIR* from opendir() */
+  
+};
+
+/**
+ * Open a directory to iterate over.
+ *
+ * @param filename the directory name
+ * @param error exception return object or #NULL
+ * @returns new iterator, or #NULL on error
+ */
+DBusDirIter*
+_dbus_directory_open (const DBusString *filename,
+                      DBusError        *error)
+{
+  DIR *d;
+  DBusDirIter *iter;
+  const char *filename_c;
+
+  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+  
+  filename_c = _dbus_string_get_const_data (filename);
+
+  d = opendir (filename_c);
+  if (d == NULL)
+    {
+      dbus_set_error (error, _dbus_error_from_errno (errno),
+                      "Failed to read directory \"%s\": %s",
+                      filename_c,
+                      _dbus_strerror (errno));
+      return NULL;
+    }
+  iter = dbus_new0 (DBusDirIter, 1);
+  if (iter == NULL)
+    {
+      closedir (d);
+      dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
+                      "Could not allocate memory for directory iterator");
+      return NULL;
+    }
+
+  iter->d = d;
+
+  return iter;
+}
+
+/**
+ * Get next file in the directory. Will not return "." or ".."  on
+ * UNIX. If an error occurs, the contents of "filename" are
+ * undefined. The error is never set if the function succeeds.
+ *
+ * @todo for thread safety, I think we have to use
+ * readdir_r(). (GLib has the same issue, should file a bug.)
+ *
+ * @param iter the iterator
+ * @param filename string to be set to the next file in the dir
+ * @param error return location for error
+ * @returns #TRUE if filename was filled in with a new filename
+ */
+dbus_bool_t
+_dbus_directory_get_next_file (DBusDirIter      *iter,
+                               DBusString       *filename,
+                               DBusError        *error)
+{
+  struct dirent *ent;
+
+  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
+  
+ again:
+  errno = 0;
+  ent = readdir (iter->d);
+  if (ent == NULL)
+    {
+      if (errno != 0)
+        dbus_set_error (error,
+                        _dbus_error_from_errno (errno),
+                        "%s", _dbus_strerror (errno));
+      return FALSE;
+    }
+  else if (ent->d_name[0] == '.' &&
+           (ent->d_name[1] == '\0' ||
+            (ent->d_name[1] == '.' && ent->d_name[2] == '\0')))
+    goto again;
+  else
+    {
+      _dbus_string_set_length (filename, 0);
+      if (!_dbus_string_append (filename, ent->d_name))
+        {
+          dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
+                          "No memory to read directory entry");
+          return FALSE;
+        }
+      else
+        return TRUE;
+    }
+}
+
+/**
+ * Closes a directory iteration.
+ */
+void
+_dbus_directory_close (DBusDirIter *iter)
+{
+  closedir (iter->d);
+  dbus_free (iter);
+}
+
+static dbus_bool_t
+fill_user_info_from_group (struct group  *g,
+                           DBusGroupInfo *info,
+                           DBusError     *error)
+{
+  _dbus_assert (g->gr_name != NULL);
+  
+  info->gid = g->gr_gid;
+  info->groupname = _dbus_strdup (g->gr_name);
+
+  /* info->members = dbus_strdupv (g->gr_mem) */
+  
+  if (info->groupname == NULL)
+    {
+      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+static dbus_bool_t
+fill_group_info (DBusGroupInfo    *info,
+                 dbus_gid_t        gid,
+                 const DBusString *groupname,
+                 DBusError        *error)
+{
+  const char *group_c_str;
+
+  _dbus_assert (groupname != NULL || gid != DBUS_GID_UNSET);
+  _dbus_assert (groupname == NULL || gid == DBUS_GID_UNSET);
+
+  if (groupname)
+    group_c_str = _dbus_string_get_const_data (groupname);
+  else
+    group_c_str = NULL;
+  
+  /* For now assuming that the getgrnam() and getgrgid() flavors
+   * always correspond to the pwnam flavors, if not we have
+   * to add more configure checks.
+   */
+  
+#if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R)
+  {
+    struct group *g;
+    int result;
+    char buf[1024];
+    struct group g_str;
+
+    g = NULL;
+#ifdef HAVE_POSIX_GETPWNAM_R
+
+    if (group_c_str)
+      result = getgrnam_r (group_c_str, &g_str, buf, sizeof (buf),
+                           &g);
+    else
+      result = getgrgid_r (gid, &g_str, buf, sizeof (buf),
+                           &g);
+#else
+    g = getgrnam_r (group_c_str, &g_str, buf, sizeof (buf));
+    result = 0;
+#endif /* !HAVE_POSIX_GETPWNAM_R */
+    if (result == 0 && g == &g_str)
+      {
+        return fill_user_info_from_group (g, info, error);
+      }
+    else
+      {
+        dbus_set_error (error, _dbus_error_from_errno (errno),
+                        "Group %s unknown or failed to look it up\n",
+                        group_c_str ? group_c_str : "???");
+        return FALSE;
+      }
+  }
+#else /* ! HAVE_GETPWNAM_R */
+  {
+    /* I guess we're screwed on thread safety here */
+    struct group *g;
+
+    g = getgrnam (group_c_str);
+
+    if (g != NULL)
+      {
+        return fill_user_info_from_group (g, info, error);
+      }
+    else
+      {
+        dbus_set_error (error, _dbus_error_from_errno (errno),
+                        "Group %s unknown or failed to look it up\n",
+                        group_c_str ? group_c_str : "???");
+        return FALSE;
+      }
+  }
+#endif  /* ! HAVE_GETPWNAM_R */
+}
+
+/**
+ * Initializes the given DBusGroupInfo struct
+ * with information about the given group name.
+ *
+ * @param info the group info struct
+ * @param groupname name of group
+ * @param error the error return
+ * @returns #FALSE if error is set
+ */
+dbus_bool_t
+_dbus_group_info_fill (DBusGroupInfo    *info,
+                       const DBusString *groupname,
+                       DBusError        *error)
+{
+  return fill_group_info (info, DBUS_GID_UNSET,
+                          groupname, error);
+
+}
+
+/**
+ * Initializes the given DBusGroupInfo struct
+ * with information about the given group ID.
+ *
+ * @param info the group info struct
+ * @param gid group ID
+ * @param error the error return
+ * @returns #FALSE if error is set
+ */
+dbus_bool_t
+_dbus_group_info_fill_gid (DBusGroupInfo *info,
+                           dbus_gid_t     gid,
+                           DBusError     *error)
+{
+  return fill_group_info (info, gid, NULL, error);
+}
+
+/** @} */ /* End of DBusInternalsUtils functions */
+
+/**
+ * @addtogroup DBusString
+ *
+ * @{
+ */
+/**
+ * Get the directory name from a complete filename
+ * @param filename the filename
+ * @param dirname string to append directory name to
+ * @returns #FALSE if no memory
+ */
+dbus_bool_t
+_dbus_string_get_dirname  (const DBusString *filename,
+                           DBusString       *dirname)
+{
+  int sep;
+  
+  _dbus_assert (filename != dirname);
+  _dbus_assert (filename != NULL);
+  _dbus_assert (dirname != NULL);
+
+  /* Ignore any separators on the end */
+  sep = _dbus_string_get_length (filename);
+  if (sep == 0)
+    return _dbus_string_append (dirname, "."); /* empty string passed in */
+    
+  while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
+    --sep;
+
+  _dbus_assert (sep >= 0);
+  
+  if (sep == 0)
+    return _dbus_string_append (dirname, "/");
+  
+  /* Now find the previous separator */
+  _dbus_string_find_byte_backward (filename, sep, '/', &sep);
+  if (sep < 0)
+    return _dbus_string_append (dirname, ".");
+  
+  /* skip multiple separators */
+  while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
+    --sep;
+
+  _dbus_assert (sep >= 0);
+  
+  if (sep == 0 &&
+      _dbus_string_get_byte (filename, 0) == '/')
+    return _dbus_string_append (dirname, "/");
+  else
+    return _dbus_string_copy_len (filename, 0, sep - 0,
+                                  dirname, _dbus_string_get_length (dirname));
+}
+/** @} */ /* DBusString stuff */
+